Tamperproof carton



June 5, 1962 M. w. KUCHENBECKER ETAL 3,037,681

TAMPERFROOF CARTON Filed Sept. 12, 1961 2 Sheets-Sheet 1 Woke/5 IZ/fucHE/VeEc/I R A ok/n/M/ d, Arm/w ATTORNEYS United States Patent Ofifice 3,937,581 Patented June 5, 1962 3,037,681 TAMPERPROOF CARTON Morris W. Kuchenbecker, Neenah, and Norman J. Asman, Appleton, Wis., assignors to American Can Company, New York, N.Y., a corporation of New Jersey Filed Sept. 12, 1961, Ser. No. 137,595 Claims. (Cl. 229-39) This invention relates to a tamperproof carton which can be made from a single blank, of a type suitable for a variety of uses such as the packaging of food products. More specifically, the invention may with particular advantage be used as a carton for packaging frozen foods such as pies.

Oustoma-rily, frozen foods are packed in end locking cartons in which the end panels are securely and substantial-ly immovably locked together. The configuration of the locking means is such that when the blanks are laid out they cannot be perfectly dovetailed together. Not only does this mean that a certain amount of waste or broke is inevitable, but also that a subsequent operation is necessary to remove the broke or waste from the area between adjacent blanks. From the standpoint of economy of operation, it is therefore desirable to produce securely locked cartons from blanks that can be perfectly dovetailed when laid out on a sheet.

It is therefore an object of the present invention to provide a tamperproof carton which can be produced from a carton blank which can be perfectly dovetailed with immediately adjacent carton blanks.

Yet another object of the present invention is to provide carton locking means which securely locks the opposing panels together with a minimum amount of lateral movement or racking motion between the locked panels.

Still another object of the present invention is to provide a carton which can be readily setup and closed on automatic equipment.

A further object of the present invention is to provide a carton construction which involves a mini-mum amount of die cutting in forming the carton blank.

According to the present invention a carton is produced from a blank in which the projecting male looking elements on one side of the blank define the recessed female locking elements for the adjacent carton blank and in which the co-acting recessed female elements in another side of the blank are formed by the projecting male locking elements in another adjacent blank. The configuration of the locking elements is such that there is no broke or waste between adjacent carton blanks. When the locking elements are engaged in the completed carton, they are held in tight relationship by edge to edge abutment of the elements themselves as well as by the edges of the opposed panels containing the locking elements.

Further details, advantages and objects of the invention will be apparent from the following specification and appended drawings wherein:

FIGURE 1 is a plan view of a fragment of a continuous web suitably out and scored to form a plurality of successive mating or dovetailed carton blanks,

FIGURE 2 is a fragmental perspective View of the blank A shown in FIGURE 1 partially set up,

FIGURE 3 is a fragmental perspective view of the completed carton showing the end locked,

FIGURE 3A is a partial sectional view of the closed carton taken along line 3A-3A of FIGURE 3, showing the inside surface of the locked end panels,

FIGURE 4 is a partial sectional view of the closed carton taken along line 44 of FIGURE 3,

FIGURE 5 is a partial sectional view of the closed carton taken along line 55 of FIGURE 3, and

FIGURE 6 is a plan view of a modified fragment of a continuous web suitably cut and scored to provide a plurality of successive mating carton blanks.

Referring to FIGURE 1, the carton of the present invention can be made from an integral blank which can be cut out from a continuous web of sheet material, such as cardboard, without loss of stock between successively cut blanks, or the need to remove broke or waste between adjacent blanks. A fragmental portion of a web is shown in FIGURE 1 which is suitably cut and scored to provide successive blanks A and A which are cut in dovetailed relation :so as to eliminate the loss of any sheet material stock. The carton is made of a single foldable blank A. The blank is divided by score lines 1046 and cut lines .2431 into hingedly connected panels and flaps including main panels 51, 53, side panel 52, partial side panels 50, 54, end panels 56, 58, 61, 63, side panel flaps 5'7, 62 and partial side panel flaps 55, 59, 60, 64.

The outer edges of end panels 56, 58, 61 and 66 have alternating male and female locking elements formed thereon, whose function in closing the car-ton will be described more fully hereinafter. A typical male locking element 35 is shown extending from and panel 56. The outer edge is defined by portions 35a and 35b while out lines 38 at intersection 37 of the outer edges of the panel extend to terminating points 39 defining an intervening throat portion of the element. On panel 53 a female locking element is defined on the edge of the end panel by portion 40a, and adjacent cut lines 43 which intersect portion tla at 42. The cut lines serve the dual purpose of defining a throat portion for the adjacent male elements 45 as well as comprising part of the female elements. It is therefore readily apparent that part of the locking elements are common to both the male and female locking elements, and that the width of the male elements is essentially equal to the Width of the female elements.

The blank A is formed into a giued carton shell by folding partial side panel outwardly about score line 10 to lie directly superposed on main panel 51. Glue is then applied along the edge of the panel 5t} opposite score line 10. Main panel 53 with partial side panel 54 hingedly connected thereto is folded outwardly about score line 13 to lie superposed on main panel 51. Partial side panel 54 then overlies and is adhered to the adhesive bearing surface of panel 50. In such condition, the shell may be shipped economically to the produce packager for set up, filling and closing.

FIGURE 2 depicts an initial stage in which the carton is squared and ready for filling. When the shell is squared, panels 50, 51, 52, 53 and 54 are positioned consecutively at right angles to each other. Usually one end of the carton is closed, the carton filled and then the other end closed.

Since the closing steps are the same for both ends of the carton reference is had to closing just one end of the carton. In closing the carton, side panel flap 57 and partial side panel flaps and 59 are folded in first. Next end panels 5'6 and 58 are infolded simultaneously about score lines 15 and 17. As the outer edges of the panels approach each other, the male elements 35 are bent or folded slightly inwardly of the planes of the end panels. The male elements then pass under the opposed female elements as the opposed endpanels are brought into contact. The closure is completed by the engagement of the opposed female and male locking elements so that the end panels lie fiat in superposed relationship as shown in FIGURE 3.

FIGURE 3A shows the inside surface of the locked closure flaps of FIGURE 3 with the dust flaps shown dotted so as not to cover up the end panel locking configuration.

The particular locking relationship of the elements in the end panels is shown in cross-section in FIGURES 4 and 5. Referring first to FIGURE 4, a view taken through the middle of an opposed interlocked male-female element shows the resulting location of the parts. The male element 45 projecting from end panel 58 underlies the end panel 56 with 41 defining the outer edge of the male element 45. Similarly point 36, on the male element projecting from end panel 56 which underlies end panel 58 but which is offset from the first described male element 45 of this view, defines the outer edge of the male element 35. Points 37 and 42 which represent junctures of the inner cut lines 38 and 43, respectively, with the outer edges 35b and 40b of the male elements 35 and 45, respectively, are depressed out of the planes of their respective end panels from which they project. This depression is occasioned by the alternate overlapping of the female elements so that the lateral portions of the male elements are forced further down relative to the rest of the elements. Because of the staggered overlapping relationship, the edges 34 and 40a of alternate female elements are visible in FIGURE 4.

FIGURE shows the particular relationship of the locking elements which insures a tight fitting, anti-racking tamperproof carton. The cross section taken through line 55 of FIGURE 3 shows that a double abutment of opposed carton edges produces the secure locking relationship according to the carton of the present invention. At this particular point the edges of two adjacent female elements are sloping in different directions. Therefore at the point where they cross they abut each other in edge to edge relationship. When a pull is exerted on each of the end panels away from each other this abutment resists such a pull preventing unlocking of the carton. Similarly, the inner edges of the male locking elements 35 and 45 defined by cut lines 38 and 43 abut each other in edge to edge relationship. This abutment similar to that of the female elements resists a pulling force tending to separate the end panels. As in FIGURE 4, the depressed lateral extremities 37 and 42 of the male locking elements 35 and 45 are visible being positioned below the rest of the locking elements. The double abutments positioned at intervals across the superposed end panels provides a complete end closure.

The use of angled cut lines 38 and 43 provides the anti-racking feature to the completed closed carton. They not only prevent unlocking but because of the abutment prevent shifting of the end panels laterally relative to each other. If straight cut lines parallel to score lines 15, 17, 20 and 22 are employed, the carton still is tamperproof, but the end panels may shift laterally with respect to each other.

Referring to FIGURE 6, modified carton blanks B and B according to the present invention is shown. These blanks are cut and scored similar to blanks A and A' and the same parts are indicated by the same numerals as in FIGURE 1 increased by a hundred so that it will not be necessary to repeat the same description. Blank B has two full side panels 150 and 152 giving uninterrupted printing surfaces. The blank is folded and glued to form a carton shell in the same manner as described previously for the blank shown in FIGURE 1. Since the squaring, filling and closing of the carton is done in the manner previously herein described, reference is made to such description to obtain a completed closed carton employing the modified carton blank.

FIGURES 1 and 6 both show the carton blanks completely dovetailed with adjacent carton blanks. This dovetailing feature is particularly important in reducing the cost of making cartons according to this invention. Not only the extra material cost, but also the cost of removing the broke are eliminated when the carton blanks in a sheet layout can be completely dovetailed.

The present invention provides an economy tamperproof carton which is anti-racking formed from an integral blank. The carton can be readily set up, filled with the commodity to be packaged, and closed by automatic machinery. The carton is essentially tamperproof and cannot be opened without mutilation of the locking elements. The double abutment of edges in the locking elements gives increased resistance to opening of the end panels preventing accidental disengagement of the locking elements.

It is to be understood that the description of the construction given is merely illustrative of the essential features of the invention, and is not limited to the specific dimensions or contours which may be greatly varied or modified and which variations are intended to be included within the scope of the appended claims.

We claim:

1. A tamperproof carton formed of a single blank suitably cut and scored comprising a pair of opposed main panels, opposed side panels hingedly connected to said main panels, a pair of end closure panels hingedly connected to said main panels; a plurality of male locking elements extending from the edges of the end panels opposite their hinge connections to said main panels each of said elements having an outer edge, edges tapering away from each other from each end of the outer edge toward the hinge line connecting said end panel to the main panel, and interior cut lines located inside the end panel intersecting said tapering edges, said out lines forming interior edges and a centered throat portion for each of said male elements; a plurality of female locking elements located opposite said male locking elements and being of width essentially equal to the width of said male locking elements, the female locking elements in each of the end panels alternating with the male locking elements, each of said female elements having a continuous shaped marginal edge including a central segment intermediate the tapering edges of adjacent male elements and terminal segments defined by the said interior cut lines extending from the ends of the central segment; the configuration of the closed carton being such that the male locking elements of each end panel are engaged in the female locking elements located in the end panel opposite them; said locking relationship being maintained by the abutment of the adjacent interior edges of the male elements extending from the end closure panels.

2. The carton of claim 1 wherein the central segment in said female elements is parallel to said hinge connections of said end panels and the terminal segments are straight lines.

3. The carton of claim 2 wherein the centered throat portion of each male locking element is approximately equal in width to the said central segment of each female locking element.

4. A tamperproof carton formed of a single blank suitably cut and score comprising a pair of opposed main panels, opposed side panels hingedly connected to said main panels, a pair of end closure panels hingedly connected to said main panels; each of said end panels having alternating male and female locking elements along the edge of the panel opposite its hinge connection to said main panel with a male element in one panel located opposite a female element in the other end panel; said male elements extending outwardly from the edges of the end panels and being defined by an outer edge parallel the end panel hinge connection, edges tapering away from each other from each end of the outer edge toward the said hinge connection and internal cut lines located inside the end panel intersecting said tapering edges and tapering towards each other, said out lines forming a centered throat portion for each of said male elements; said female elements being of width essentially equal to the width of said male locking elements, each of said female elements having a continuous shaped marginal edge including a central segment essentially equal in length to the width of said centered throat portion and parallel to said end panel hinge connection, said central segment extending between the tapering edges of adjacent male elements, and terminal segments at the ends of the central segment defined by the said internal cut lines; the configuration of the closed carton being such that the male locking elements of each end panel are engaged in the female locking elements located in the end panel opposite them.

5. A locking means for a carton, said carton having two panels to be locked together lying in essentially parallel edge contacting relationship; said means comprising alternating male and female locking elements located along the contacting edges of the panels with a male element in one panel located opposite a female element in the other panel; said male elements extending outwardly from the contacting edges of the panels and being defined by an outer edge, edges tapering away from each other and toward the contacting edge of the panel and internal cut lines located inside the panel intersecting said tapering edges and tapering towards each other, said cut lines forming a centered throat portion for each of said male elements,

said female elements being of width essentially equal to 20 the width of said male locking elements, each of said female elements having a continuous shaped marginal edge including a central segment essentially equal in length to the width of said centered throat portion and essentially parallel to said contacting edge, said central segment extending between the tapering edges of adjacent male elements, and terminal segments at the ends of the central segment defined by the said internal cut lines; the configuration of the locked panels being such that the male locking elements of each panel are engaged in the female locking elements located in the panel opposite them.

References Cited in the file of this patent UNITED STATES PATENTS 1,523,246 Berkowitz Jan. 13, 1925 2,406,123 Zalkind Aug. 20, 1946 2,962,202 Hansen Nov. 29, 1960 FOREIGN PATENTS 1,837 Great Britain of 1889 

